Treatment of textile materials



Patented May 30, 1939 STATES 2,160,176 TREATMENT OF TEXTILE MATERIALS No Drawing. Application January 13, 1938, Serial No. 184,766

6 Claims.

This invention relates to the treatment of textile materials especially cellulosic fiber, whereby to impart thereto permanent water-repellent characteristics.

It is an object of this invention to provide an improved process for water-proofing cellulosic fiber without at the same time unduly damaging the tensile strength f the fiber. Other and further important objects of this invention will appear as the description proceeds.

In British Patent No. 477,991, granted to Baldwin, Evans and Salkeld and their assignee, there is described a process for treating cellulosic materials whereby to impart thereto water-repellent properties. The said process consists of treating the fiber in aqueous solution with a compound of the general formula RCONH-CHz-Ndert) X, wherein R. is the alkyl radical of a long-chain fatty acid, N(tert) stands for a molecule of a tertiary base such as pyridine, quinoline or trimethyl-amine, while X stands for a monovalent acid group.

The said treatment generally consists of two steps. First, the fiber or fabric is impregnated with an aqueous bath containing from 0.01 to 2% by weight of said quaternary compound, and is squeezed out and dried at a temperature not above 45 G. Then the dried fabric is subjected to a baking step, that is it is heated in the absence of moisture at a temperature of about 105 to 120 C.

It has been found that during said procedure the fiber is somewhat tendered; that is, its tensile strength is diminished, very probably due to contact with free acid which is liberated during the baking step. The object of my invention, accordingly, is to devise a method for accomplishing water-repellency in textile fiber without simultaneously injuring unduly its tensile strength.

I have now found that the above objects of this invention can be accomplished by proceeding substantially in the manner set forth in said British Patent No. 477,991, but using in lieu of the reagent therein indicated, a similar quaternary compound derived from a weak acid. In other words I have found that when cellulosic fiber or fabric is treated with a quarternary compound of the general formula wherein R and N(tert) have the same significance as above, but wherein X is the radical of a weak acid such as acetic or formic, or in general an acid whose dissociation constant is less than 0.01, good, permanent, water-repellent characteristics can be imparted to the fiber, without materially impairing the strength of the fiber.

The compounds which I employ for the purpose of this invention are in themselves novel compounds and are more fully described and claimed in my copending application Ser. No. 184,765 of even date herewith (Patent No. 2,146,408, issued February 7, 1939. Briefly stated the synthesis of these compounds is as follows; An alkyl amide of the formula RCONHz, for instance stearamide, 10

Acetic Sulianilic Formic Tartaric Lactic Phthalic Salicylic Glycollic or in general, any organic acid which has a dissociation constant'less than 0.01 and which is capable of being melted or dissolved in a diluent at the temperature of the reaction. The dissociation constant for the acids specifically indicated above lies between 0.00001 and 0.002.

When a lower fatty acid is employed, the resulting quaternary compound tends to become insoluble as the length of the chain in the acid is increased. This however may be oil-set by choosing an acid which has additional solubilizing groups as is illustrated in the case of lactic and tartaric acids.

The actual steps of procedure in my improved processof treating fiber may in general follow the procedure indicated by Baldwin, Evans and Salkeld in their aforementioned British patent. Thus the treatment is preferably divided into two steps. In the first step, the cellulosic material is impregnated with an aqueous solution of the quaternary compound at a temperature below 40 C. The concentration of the solution may vary from 0.1% to 4%.. The fabric is padded in this solution and then squeezed out until it contains an amount of solution about equal in weight to the weight of the fabric. The fabric is then dried at a temperature not exceeding 40 0., although under special conditions, for

' described is of a structure.

instance in a brisk current of hot air, the drying temperature may rise to as high as C.

In the second step of the procedure, the dried fabric is heated in the absence of moisture at a temperature between and 140 C. preferably around 120 to 130 C. This step, which is called the baking step, generally takes about 5 minutes but with higher temperatures a shorter period, even 1% minutes may suflice. The baking may be done in an oven or on a drum drier. The fabric is then thoroughly scoured.

If desired, the drying step and baking step may be run continuously in' the same apparatus.

The resulting fabric is characterized by a softer feel as compared to the original fabric and by the property of shedding water. When a drop of water is let fall on the fabric from a pipette, it assumes a globular shape and runs of! the fabric without moistenlng the same.

An additional characteristic of the fabric so treated is that the water-repellent effect above permanent nature; that is, it is not removed by laundering, even in the presence of alkali and soap. Other erties may likewise be imparted to the fabric incidentally, depending on the conditions of operations. For instance, if the fabric has been dyed with direct or acid colors which themselves are not very fast to washing, their fastness on the fabric becomes greatly improved.

As alkyl amides of the formula RCONH2 in the above general formula of the quaternary compound, may be used any of the amides suggested in said copending application Ser. No. 184,765 (Patent No. 2,146,408); for instance, stearamlde, oleylamide, lauramide or, in general, any alkyl amide, whether saturated or unsaturated, having from 7 to 19 carbon atoms in its As tertiary base for the member above, likewise, any of the bases mentioned in said copending application may be employed; for instance, pyridine, picoline, quincline, trimethyl-amine, triethanol amine, etc. For practical reasons pyridine is preferred.

Without limiting my invention to any particular procedure, the following examples in which parts by weight are given will serve to illustrate my preferred mode of operation.

EXAMPLE I A. Preparation of the quaternary compound 10 parts of steal-amide, 2 parts para-formaldehyde and 20 parts glacial acetic acid were heated, in a flask with a reflux condenser attached, for 40 minutes at 80 C. At the end of this time a homogeneous solution had formed. 10 parts of pyridine were then added and the heating was continued for 3 hours. From time to time one drop samples were removed and tested for solubility by adding the same to cc. of. water at a temperature of 40 to 50 C. and observing whether an insoluble residue remains. The final sample readily formed a paste with water and dissolved to form an opalescent solution which foamed copiously on stirring. Presumably, the final product was largely stearamido-methylpyridinium acetate.

B. Treatment of fabric A sample of a broadcloth fabric was treated with a 1% solution of the product prepared in paragrah A, and was then run through a wringer with the pressure adjusted to give a 100% weight increase, and dried at 40 C. When thoroughly dry, it was placed in an oven, and was heated advantageous propfor 20 minutes at C. It was then given a one hour soap wash, rinsed and ironed dry. The sample thus obtained was compared for waterrepellency and for tensile strength with samples similarly treated with stearamidomethyl-pyridinium-chloride, prepared by methods described ln the prior art cited above. A sample of untreated fabric was also evaluated at the same time. i

The sample of this invention was found equal in every respect to the samples treated with stearamido-methyl-pyridinium chloride, as far as water-repellent effects are concerned. It was found vastly superior to the said other samples in tensile strength, and was in fact close in tensile strength to a sample of the same fabric which had not been treated at all except for washing.

EXAMPLE II The process of Example 1B was repeated using a bath of 4% concentration in lieu of the 1% bath therein employed. The resulting fabric had excellent water-repellency and was superior ln tensile strength to samples which had received treatment with the chloride.

EXAMPLE III A mixture of 10 parts of stearamide, 2 parts of parafonnaldehyde and 20 parts of 90% formic acid was heated for one hour at 80 C. The mixture did not completely dissolve but remained as a thin heterogeneous paste. Next, 10 parts of pyridine were added and the heating continued for two hours. At the end of this time the sample Was water soluble. The product, presumably stearamidomethyl-pyridinium formate, was applied to a broadcloth fabric and evaluated by the methods described in Example I.

The resulting fabric possessed excellent waterrepellency and highly satisfactory tensile strength both when treated with a 1% bath and with a 4% bath. It will be noted that the 4% bath is a very severe test, and that a bath of this concentration is prohibitive in the case of the quaternary pyridinium chloride. With the above formate compound, however, the treatment was highly satisfactory from every viewpoint.

EXAMPLE IV A mixture of 10 parts of the amides derived from hydrogenated peanut oil by treatment with ammonia in the presence of a catalyst, 2 parts of para-formaldehyde and-20 parts of 90% formic acid was heated for 1 hour at 80 C. At the end of this time 10 parts of pyridine were added and the heating was continued for 2 hours more. At the end of this heating period the product dissolved completely in water to give a slightly milky opalescent solution.

A cotton fabric was impregnated with a 2% solution of this product, dried and baked for 20 minutes at 120 C. The fabric was then boiled for 1 hour in a solution containing 0.25% soap and 010% soda ash. After drying, the fabric was found to have excellent water repellency and was not appreciably tendered. The fabric was also permanently softened by this treatment.

EXAMPLE V The product described in Example III was applied to a light weight woolen fabric; the latter was then run through a wringer, dried at 40 C.,

and heated 15 minutes at 120 C. The fabric was then soap-scoured and dried. It was found to have good water repellency as indicated by its resistance to wetting when a drop of water was rolled about on its surface.

In a similar mannerother quaternary compounds derived from higher fatty acid amides and weak organic acids, may be applied to textile fiber of vegetable or animal origin, for instance the compounds described in my copending application Serial No. 184,765 (Patent No. 2,146,408) and derived from stearamide, lauramide, or oleyl amide on the one hand, and from glycollic acid, phthalic anhydride, tartaric, salicylic or lactic acid on the other hand.

It will be understood that the details set forth in the above examples may be varied within wide limits without departing from the spirit of this invention as defined by the subjoined claims.

I claim:

1. The process of treating textile material whereby to impart thereto water-repellent properties, which comprises impregnating the same with a compound of the general formula RCONH-CH2-N (tert) X,

wherein R. is an alkyl radical containing not less than 7 carbon atoms, N(tert) represents the molecule of a tertiary base, and xtstands for the acidic radical of an organic acid whose dissociation constant is less than 0.01, and then subjecting the impregnated material to heat treatment in the absence of moisture at a temperature between and 140 C.

2. The process of treating textile material whereby to impart thereto water-repellent properties, which comprises impregnating the same with a compound of the general formula RCONH-CHa-N'Gert) -x,

wherein R is an alkyl radical containing not less than 7 carbon atoms, N(tert) represents the molecule of a tertiary base, and X stands for the acidic radical of an organic acid whose dissociation constant is between 0.00001 and 0.002, and then subjecting the impregnated material to heat treatment in the absence of moisture at a temperature of about to C.

3. The process of treating cellulosic material .which comprises impregnating the same with an aqueous solution of a compound of the general formula R-CON'H-CHrN-X wherein R. is an alkyl radical having from I to 19 carbon atoms in its structure and X is an organic carboxylic acid having a dissociation constant between 0.00001 and 0.002, drying impregnating material at a temperature not exceeding 40 C. and then heating said material in the absence of moisture at a temperature of between 90 and C. A

4. The process of treating cellulosic material whereby to impart thereto permanent water-repellent properties which comprises impregnating the same with an aqueous solution of stearamidomethyl-pyridinium acetate, drying the material at a temperature not exceeding 40 C. and then heating said material in the absence of moisture at a temperature of about 120 to 130.

5. The process of treating cellulosic material whereby to impart thereto permanent water-repellent properties which comprises impregnating the same with an aqueous solution of stearamidomethyl-pyridinium formate, drying the material at a temperature not exceeding 40 C. and then heating said material in the absence of moisture at a temperature of about 120 to 130 C.

6. The process of treating cellulosic material whereby to impart thereto permanent water-repellent properties, which comprises impregnating the same with an aqueous solution of stearamidomethyl-pyridinium phthalate, drying the material at a temperature not exceeding 40 C. and then heating said material in the absence of moisture at a temperature of about 120 to 130 C.

JOSEPH BARREL SHIPP. 

